Message4498

Here is an old list of ideas for our driver script that has never made it onto
the tracker:
1. optionally run validator
2. handle single-file PDDL input
3. handle compressed input (xz etc.)
4. handle pipelining between components
5. refactor portfolio code, see issue414 (is this still current?)
6. when search is not run, options should go to first component being run by default